Do not convert from RectF to Rect by flooring.

content/renderer/render_widget.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 953 matching lines @@
                                        &optimized_copy_rect,
                                        &dib_scale_factor)) {
     // Only update the part of the plugin that actually changed.
     optimized_copy_rect = optimized_copy_rect.Intersect(bounds);
     pending_update_params_->bitmap = dib->id();
     pending_update_params_->bitmap_rect = optimized_copy_location;
     pending_update_params_->copy_rects.push_back(optimized_copy_rect);
     pending_update_params_->scale_factor = dib_scale_factor;
   } else if (!is_accelerated_compositing_active_) {
     // Compute a buffer for painting and cache it.
-    gfx::Rect pixel_bounds = bounds.Scale(device_scale_factor_);
+    gfx::Rect pixel_bounds = bounds.ScaleUnsafe(device_scale_factor_);
     scoped_ptr<skia::PlatformCanvas> canvas(
         RenderProcess::current()->GetDrawingCanvas(&current_paint_buf_,
                                                    pixel_bounds));
     if (!canvas.get()) {
       NOTREACHED();
       return;
     }
 
     // We may get back a smaller canvas than we asked for.
     // TODO(darin): This seems like it could cause painting problems!
@@ skipping 878 matching lines @@
   pending_smooth_scroll_gestures_.insert(std::make_pair(id, callback));
 }
 
 bool RenderWidget::WillHandleMouseEvent(const WebKit::WebMouseEvent& event) {
   return false;
 }
 
 bool RenderWidget::WebWidgetHandlesCompositorScheduling() const {
   return false;
 }